The challenge mystery bag is a reward for completing Daily Challenges that requires turning in items that had to be made. It contains a number of certain items, listed below, with a monetary value approximately equal to the items handed in, along with a relatively small amount of gold coins.

The rewards below are given depending on how much your challenge earned in items gathered or cost. So according to Jagex your challenge bag will give back the amount of gold in items/coins using current Grand Exchange prices, however this may fluctate in wealth.

For example: on a challenge in which you must make Summer pies, the bag will reimburse you for roughly how much the Strawberry, Watermelon, Cooking apple, and Pie shell cost. If you opted to buy Raw summer pies instead (much more expensive): you will NOT be reimbursed the higher amount. So for the most balanced outcome, it's best to choose the cheaper option to complete your challenge.

This bag, along with the Bag of lost items, allowed a player to obtain two or more stacks of bank notes of the same item, by opening a bag and obtaining a stack of noted items as reward that you already have in your inventory. This has been patched as of 9 July2013.

There is currently a bug that causes free players to receive members-only items as rewards from Challenge Mystery Bags, meaning that free players cannot use some challenge rewards, however they may be sold.